I have one of these steam based warframe packs and I picked it up from the steam summer sale for 75% off.

As mentioned above, it can only be activated on to you steam account once as they are considered DLC.

The top warframe packs were always a big turn off for me. You're getting a ton of plat out of them and you'll be pretty much set to buy everything in the game.
I'm not one to buy things you can get through the game itself, part of the progressive side of warframe for me is working towards getting the warframe parts and equipment.

This is my way of playing though and I have no problem if people want to pay real money to enjoy a game sooner rather than later

The starter pack I picked up through steam got me the plat to buy enough warframe slots so I had room for all the frames. It also gave me enough weapon and companion slots to have a huge variety when it came to the equipment I could use.
I think the starter pack cost me around $6.50 aussie at the time. I was able to reduce the cost due to the steam cash I had to go towards it through trading in free cards.

Cheaper packs and plat come along a few times a year and it's worth waiting for them or the log in reward version if you are considering the market currency option

I'm much in the same mind as roob, in that I want to get what parts are available in game, in game. Plat has mostly been towards weapon/frame slots and cosmetics. There will always be new weapons/frames to buy slots for =)

It's mostly to not hamstring myself in terms of content available though. For me, buying a frame is game time I'm not playing.

I admit to having paid once for Oxium though. Goddamn that Oxium. 30plat for 300 is totally worth it.

I'll spend the money to support the devs, but I don't want to shortcut my game at the same time, so pure plat is the purchase path for me, generally. Especially as the only 'exclusive' gear from prime access has been Excal Prime, and that's not gainable anymore. All subsequent prime gear has been released out in the Void after an iteration or two.

I've found, over time, that DE tend to listen quite well to the community, and stuff that I find irritating first off, like the Beacon grind, gets fixed after a few patches. Also, Kubrow management coming sooner.

Also, being F2P, Warframe is very easy to drop as a game and pick back up after a few months.

Vauban never was an issue for me, actively farming it is impossible, so I just took the alerts as they came. It might have been easier earlier on, when the alert pool was smaller.

Ah. You guys missed all the good returns. I spent money on the cheap founders pack, and later on they decided to reward us with real world loot!
I got a ninja bandana, and the people who bought the next highest pack actually got Warframe T-shirts!
You really don't need much plat. I never used all of the plat I got for my one off $60 spend.
I used it to by frame and weapon slots, colour pallets, a few sentinels and even splurged on one of the bulk weapon skin packs.